They said some passengers grew suspicious about the behaviour of V P Niyas, and one among them alerted railway authorities.
Niyas was arrested by RPF when the train halted at Kanhangad station, police said.
A check revealed he did not possess any identity card nor was he wearing the required uniform.
A southern railway release said that considering the seriousness of the incident, Senior Divisional Manager (Commercial), Palakkad, P A Dhananjayan directed all ticket checking staff of the division to wear their uniform and identity card and show it to passengers on demand.